Colorado’s top money managers are promoting the final two elements of a three-part plan to strengthen the state’s financial reserves to withstand the inevitable next downturn in the economy — without the devastating cuts in highways and higher education triggered by the last recession.

The Joint Budget Committee already has put the first part of the fiscal stability plan into effect over the last few years by quietly refilling a host of special reserve funds that were raided to survive the budget crisis that crippled the state before voters approved Referendum C in 2005.

The budget approved this week for the fiscal year that begins next July 1 is the fourth written under that five-year reprieve from the automatic tax rebates that would otherwise have been mandated by 1992 Taxpayer’s Bill of Rights. With the Ref C clock running out, JBC chairman Bernie Buescher, D-Grand Junction, wants to follow the restocking of special reserve funds with two reforms:

• A bill channeling part of future windfalls from federal mineral leases on the Roan Plateau and other federal lands into a special permanent fund for higher education.

• A six-month delay in transferring “excess” budget reserves to the Highway Users Tax Fund. That bill wouldn’t change the nominal 4 percent state general fund reserve, but by delaying the transfer of supposed “excess” funds until legislators know what the state really has collected in revenues for the upcoming budget year, it would make our puny rainy-day fund more effective.

We’ve editorialized repeatedly in favor of channeling some of the state’s share of oil and gas leases on federal lands into a permanent fund to benefit higher education. But as now modified at the suggestion of Todd Saliman, director of the state Office of Budget and Planning, the bill would also take some of the pressure off the state’s 4 percent general fund reserve.

As originally envisioned, only the interest from that permanent fund could have been spent for capital construction in higher education. But as it passed the Senate Education Committee on Thursday, that upcoming endowment could also be tapped in a recession to protect higher education operating budgets. That’s a fine idea, as long as the state repays such borrowing with interest when the economy rebounds.

As Buescher told The Post on Thursday, that new higher education permanent fund indirectly strengthens the general reserve. The JBC already has refilled a huge special reserve known as the Education Fund that underwrites K-12 public schools. Since K-12 spending consumes 43 percent of the general fund and higher education takes 10.5 percent, those two special reserves, and a few smaller ones, now cover 55 percent of state general fund spending. As a result, the nominal 4 percent general fund reserve — about $300 million — really has to cover only 45 percent of the $7.8 billion general fund. That means the supposed 4 percent reserve is actually about 8.8 percent of the spending it really covers. That’s much closer to the 10 percent reserve The Post has long insisted the state needs for sound management of your money.

If your head is pounding from this discussion, you’re not alone. Colorado’s crazy-quilt constitution imposes a bewildering maze of budget mandates. But state Treasurer Cary Kennedy, who has led efforts to reform the budget for 15 months, Gov. Bill Ritter and the JBC have to live with the constitution Colorado has — not the one we wish we had.

Within those constraints, the elected officials who manage your money have done a fine job of keeping the promises they made to the voters who approved Referendum C.